Need advice for testing of hypotheses related to the self-citation method

[Jorge_Stolfi]

There are two "little" problems with this that make it impossible:
1) Thinking in terms of bits and transducers would be anachronistic at a time when cryptography was at the mono-alphabetic substitution (with homophones and nulls) stage,

People back then were as smart as we are today.  (Maybe smarter, since they had no TV or facebook...) 

"Bits" and "transducers" is only our modern way of describing the process.  Just as we would say that the tables of Soyga are traces of a cellular automaton.  But people have always understood those concepts in an intuitive way, without using those words.

While complex encryption schemes were not standard common knowledge in the 1400s, as they would be in the 1500s, individual mathematicians would have been perfectly capable of devising encryption methods as complex as the "self-citation encoding" would be.  From wikipedia, for example:

• "In his book Flos, Leonardo de Pisa, also known as You are not allowed to view links. Register or Login to view. (1170–1250), was able to closely approximate the positive solution to the cubic equation x^3 + 2x^2 + 10x = 20. Writing in You are not allowed to view links. Register or Login to view. he gave the result as 1,22,7,42,33,4,40 (equivalent to 1 + 22/60 + 7/60^2 + 42/60^3 + 33/60^4 + 4/60^5 + 40/60^6), which has a You are not allowed to view links. Register or Login to view. of about 10−9.You are not allowed to view links. Register or Login to view.
  

The SCM as encryption method is not much more complex than writing a sequence of numbers where each number is the location of a word in the Bible

2) The bit sequence would need to be reconstructed from the VMS in order to recover the message. With multiple possible sources for each target word of the SCM it can't be done.

Indeed the SCM as described is a many-to-one encoding of a bit sequence to a string of words.  But
what Thorsten and Timm observed is only that the VMS often repeats sequences of words that have occurred before, with variations.  They then devised a method (the SCM) that generates random text with that same feature, while imitating a few other statistics such as the Zipf plot.  But it does not follow that the VMS was created using the SCM!  

Back in my day, Gordon Rugg observed that Voynichese words can be split into prefix/middle/suffix where each segment is picked from a small set of choices.  (This feature was noted by others before, e. g. Tiltman).  He then devised a method, using a three-column table and masking cards with slots, to generate random text that (by construction) also displayed that feature.  And he then he too "concluded" that the VMS was random gibberish with no meaning -- a "hoax".

One can easily build a 3rd-order Markov word generator that produces random text very much like Shakespearean English.  (That would be basically equivalent to the GPT model discussed in other posts here.)  The Markov-generated text will have the same vocabulary size, Zipf plot, word and character entropy, and may other statistics as the real works of Shakespeare.  Someone who does not know English would probably be unable to tel them apart. Does it follow that Shakespeare's plays are random gibberish without meaning -- a "hoax" too?

So, if the VMS was an encrypted text, the actual encoding method could have been very different from the SCM, and easily invertible; but still happened to generate repetitions and near-repetitions similar to those observed. 

All the best, --jorge